Skip to Content

SiePortal

The integrated platform for your product selection, buying and support workflow - bringing together Industry Mall and Online Support.

SiePortalDeutsch

Search

Home
Support Support
{{(apiData.Support | filter:{'rank':1}:true)[0].title}} Support
- Menu temporary not available
- Menu temporary not available
- Menue temporary not available
- {{item.title}}

Products & Services
- Menu temporary not available
- Menue temporary not available
- {{item.title}}
Support Support
{{(apiData.Support | filter:{'rank':1}:true)[0].title}} Support
- Menu temporary not available
- Menue temporary not available
- {{item.title}}
MySiePortal MySiePortal
{{(apiData.MySiePortal | filter:{'rank':1}:true)[0].title}} MySiePortal
- Menu temporary not available
- Menue temporary not available
- {{item.title}}
Cart ({{apiData.CartCount}})

Navigation

Bits of the Word Vs Bits of the Bytes

Created by: qwemx at: 12/20/2021 1:12 PM (3 Replies)

Rating (0)

Thanks 7

4 Entries

12/20/2021 1:12 PM	Rate (0)
qwemx Silver Member Joined: 12/28/2016 Last visit: 11/12/2024 Posts: 364 Rating: (6)	Hi I am using the example below as FC501 https://support.industry.siemens.com/tf/ww/en/posts/copy-data-from-16-diffrent-input-to-one-word/114417/?page=0&pageSize=10 To combine 16 Inputs in a single Word in step7 V5.5 So I haveInput1 to Input16and Output is DB1.DBW0 So I noticed that when Input1 is True it is reflected as address DB1.DBX1.0 (becomes True) which I believe is Bit 8 (Bit 0 t0 Bit 15 ) However when I use this word on HMI MP277 Wincc flexible then the Input1 is reflected as Bit 0 of the Word Tag . How to make sense of it Attachment FC501.zip (436 Downloads)
	With kind regards... qwemx
Suggestion To thank Quote Answer

12/20/2021 1:25 PM	Rate (0)
jacek d Platinum Expert Joined: 9/23/2005 Last visit: 9/15/2025 Posts: 5116 Rating: (768)	The answer is endianness. This property describes how computer systems store data longer than 1 byte in memory, i.e. what is byte order of such data. S7-300/400 are big endian. While Windows systems (on which WinCC runs) are low endian. Attachment big little endian.jpg (464 Downloads)
	Last edited by: jacek d at: 12/20/2021 13:27:11 Regards, Jacek What is confusing you is the fact that you never see a number but always its digit representation. So you end up thinking that the number is the representation. - Andrej Bauer Any claims against me - based on whatever legal reason - resulting from the use of any code and/or ideas presented on this forum shall be excluded. #StayWithUkraine
Suggestion To thank Quote Answer
This contribution was helpful to 3 thankful Users ixo65 Hati qwemx

12/20/2021 1:27 PM	Rate (0)
qwazee Platinum Expert Joined: 3/30/2020 Last visit: 9/15/2025 Posts: 5451 Rating: (1064)	Hello. In the Siemens control systems .. * bytes are numbered from LEFT -> RIGHT * bits are numbered from RIGHT -> LEFT (click to enlarge picture)
	Last edited by: qwazee at: 12/20/2021 14:26:12 fix picture; thanks Mr. Jacek Activities of this user is voluntary. There is no obligation or liability placed on this user. Though optional, your 'please' and 'thank you' is highly valued.
Suggestion To thank Quote Answer
This contribution was helpful to 2 thankful Users Hati qwemx

12/20/2021 1:41 PM	Rate (0)
jacek d Platinum Expert Joined: 9/23/2005 Last visit: 9/15/2025 Posts: 5116 Rating: (768)	There's small inaccuracy in the picture - byte limits marker position.
	Regards, Jacek What is confusing you is the fact that you never see a number but always its digit representation. So you end up thinking that the number is the representation. - Andrej Bauer Any claims against me - based on whatever legal reason - resulting from the use of any code and/or ideas presented on this forum shall be excluded. #StayWithUkraine
Suggestion To thank Quote Answer
This contribution was helpful to 2 thankful Users qwazee qwemx

|

Share this page:

Share this page on...

Follow us on